Adverse events associated with the intraoperative injection of isosulfan blue

Study objective: To describe the adverse events associated with the intraoperative injection of isosulfan blue in a large group of patients having a wide range of surgical procedures, and to identify risk factors for these events.

Design: Retrospective chart review.

Setting: University-affiliated institution specializing in malignancies

Patients: 1835 patients representing a total of 1852 surgical procedures.

Measurements: Incidence, type, severity, onset time, duration, management, and the presence of potential risk factors for adverse events. Events were considered "major" if potentially life-threatening hypotension occurred.

Main results: Adverse events occurred in 28 procedures (1.5%) and 14 of these adverse events (0.75%) were classified as major. The types of events were: skin reactions in 21 patients, hypotension in 14 patients, edema in 1 patients, and unspecified in 1 patient. The time of onset for adverse events was 42.2 +/- 53.9 minutes (median, 17.5; range, 1 to 180 min) after isosulfan blue injection, and was significantly longer for minor reactions compared with major events (p = 0.015). The longest adverse event lasted at least 21 hours. Treatment was successful with usual antiallergy/antianaphylaxis medications. Ten patients received diphenhydramine alone, and four patients received intravenous epinephrine infusions. Factors associated with a significantly increased incidence of adverse events were isosulfan blue injection in the vulvar area (p = 0.000038), and the chronic preoperative use of angiotensin-converting enzyme inhibitors or angiotensin receptor-blocking agents (p = 0.043). Trends toward an increased risk of an adverse event were noted with isosulfan blue injection in the breast area (p = 0.19), and having more than one surgical procedure with isosulfan blue (p = 0.14).

Conclusions: Although the most frequent adverse event associated with injection of isosulfan blue was a skin reaction, potentially life-threatening hypotension occurred in 0.75% of all procedures. Anesthesiologists must be aware of the variable onset time and potentially prolonged duration of the adverse events. They should recognize the need for extra vigilance in patients with potential risk factors, and have the usual antiallergy/antianaphylaxis medications available for administration if necessary.